Fuel injection nozzle for diesel engines



Aug. 7, 1956 H. LANG 2,757,967

FUEL INJECTION NOZZLE FOR DIESEL ENGINES Filed April 20, 1955 VENTOR. Heinr' Lung 5L KW ATTOR NEY' United States Patent FUEL INJECTION NOZZLE FOR DIESEL ENGINES Heinrich Lang, Munich, Germany, assignor to Durex,

S. A., Geneva, Switzerland, a corporation of Switzerland Application April 20, 1955, Serial No. 502,639

Claims priority, application Switzerland May 24, 1954 2 Claims. (Cl. 299-107.6)

My invention relates to fuel-injection nozzles for Diesel engines and more particularly to nozzles including a differential needle valve and a plurality of spray ducts emanating from a collecting or distribution chamber arranged in the tip of the nozzle body behind the valve seat in the direction of the flow of the fuel.

It has already been suggested to arrange in nozzles of the said type one central spray duct extending in the axial direction of the nozzle and at least one inclined spray duct extending substantially in radial direction of the nozzle. In such nozzles all the said ducts were substantially of the same length which equaled to the thickness of the wall in the usually conical tip of the nozzle body. The spray effect from all said ducts was the same and in view of the relatively short length of said ducts the jet of fuel after passing therethrough disintegrated into a fine mist almost immediately behind the ducts and did not reach more distant portions of the combustion space.

It is the principal object of my invention to avoid the said disadvantage and to provide a nozzle which will not only produce a widely defused spray of fuel in the combustion chamber but which will also deliver fuel to more distant portions of the combustion space. To this effect according to my invention I provide the tip of the nozzle body with an axial extension or pintle through which a primary central axial duct extends. This elongated primary duct will guide the fuel jet pressed therethrough with the result that the jet will be kept in shape and will not immediately disintegrate after having left said duct, and will safely reach any distant portion of the combustion space against which it has been directed. The lateral fuel duct or ducts also originating in said collecting or distribution chamber pass through the wall of the substantially conical tip of the nozzle at or near the base of said axial extension or pintle and are shorter and preferably also narrower than the said primary fuel duct so that the fuel jet leaving the same will quite immediately or at least very soon thereafter disintegrate and will widely and evenly distribute fuel in the portion of the combustion chamber surrounding the tip of the nozzle.

The said and other objects of my invention will be more fully understood from the following specification when read with the accompanying drawing in which one embodiment of my invention is illustrated in Fig. 1 in a sectional elevational view and in Fig. 2 in a cross sectional view on line 2-2 of Fig. 1.

As shown in the drawing the nozzle body 11 is secured to the nozzle holder by the cap nut 12. The differential needle 13 is centrally and slidably seated in said body 11 and is in any customary manner attached to a spring loaded stem or spindle 13 displaceably mounted in said holder 10. The needle 13 is provided with a 2,757,967 Patented Aug. 7, 1956 "ice tion chamber of the engine cylinder (which is not shown) passes through one or more ducts 16 of the holder 10 into a circular groove 17 of the body 11 and from there through one or more longitudinal ducts 18 into a pressure chamber 19 arranged above the valve seat 15. When the needle 13 is raised by the oil pressure and the valve tip 14 lifted from its seat 15 the fuel flows under pressure through the valve opening into the distribution chamber 20 arranged in the comically shaped tip 21 of the nozzle body 11. From there the oil passes into the combustion chamber of the cylinder through a primary axial duct 23, and through at least one lateral secondary spray duct 24 extending radially and under an angle against the nozzle axis through the tip 21 of the nozzle body 11. According to my invention the said conical tip 21 containing the said distribution chamber 20 is provided with an axial extension or pintle 22 through which said duct 23 extends from said chamber 20. The

thus elongated duct 23 guides the oil jet passing therethrough with the result that the jet is kept in shape, and does not immediately disintegrate after leaving the said duct, thus preserving its original impact. The outer orifices of the lateral spray ducts 24 are situated substantially in the transition between the conical body tip 21 and the pintle 22. These lateral ducts 24 penetrating just the wall of the tip 21 are shorter, and preferably also narrower than the axial duct 23.

It will be Well understood that the compressed oil after the needle 13 has been raised and the valve 14 opened will flow more readily and quicker through the axial jet opening 23 than through the shorter lateral spray ducts 24 and this will result in an advanced fuel injection which is often desired. To improve this effect the lateral ducts 24 may be narrower than the axial duct 23. The oil quickly and readily passing through the duct 23 will well cool the exposed pintle 22 and also the neighboring portion of the tip 21 in which the lateral spray ducts 24 are situated.

The fuel jet or jets leaving the shorter and preferably also narrower lateral ducts 24 will quite immediately or at least very soon thereafter disintegrate thus widely and evenly distributing fuel in the space of the combustion chamber surrounding the tip 21 of the nozzle.

Having shown and described one embodiment of my invention to illustrate the application of the principles thereof I wish to have it understood that my invention may be otherwise embodied without departing from such principles and without avoiding the scope of the appended claims.

What I claim as my invention is:

1. A fuel spray nozzle for Diesel engines comprising in combination a nozzle body having a substantially conically shaped tip, a valve in said body including a differential needle and a valve seat, a fuel collecting or distribution chamber substantially within said tip, a pintle extending behind said chamber from said tip in axial direction of said nozzle body; a primary fuel duct axially passing through said pintle from said collecting chamber; and at least one secondary fuel duct laterally extending from said collecting chamber through said tip of the nozzle body substantially in a direction forwardly inclined to the longitudinal axis thereof, said secondary fuel duct or ducts being shorter than the said primary fuel duct.

2. A fuel spray nozzle for Diesel engines comprising ayes/gee? 3 in combination a nozzle body having a substantially conically shaped tip, a valve in said body including a differential needle and a valve seat, a fuel collecting or distribution chamber substantially Within said tip, a pintle extending behind said chamber from said tip in axial direction of said nozzle body; a primary fuel duct axially passing through said pintle from said collecting chamber; and at least one secondary fuel duct laterally extending from said collecting chamber through said tip of the nozzle body substantially in a direction forwardly in- 10 References Cited in the file of this patent FOREIGN PATENTS Italy Oct. 6, 1938 Italy Jan. 21, 1949 

